This invention relates to manually actuated impact tools for applying a torsional force, greater than that applied manually to the tool, to threaded type fastenings, such as tools of the type shown in U.S. Pat. Nos. 2,661,647, 2,844,982, 2,954,714, 3,108,506, and 3,156,309, but relates particularly to improvements in the manual impact tools shown in my co-pending U.S. patent application Ser. No. 324,024, filed Dec. 3, 1981, issued as U.S. Pat. No. 4,382,476. Each of these patents and the said co-pending patent application, in common with this application, shows a manually operable impact tool utilizing a manually operable handle, a main power spring, and an annular inertia member carrying pawls which engage a ratchet-toothed member with an output shaft to produce, from energy derived from movement of the handle by torque applied thereto by the operator and stored in and later released by the spring, successive impacts which are delivered as torque through the output shaft to a threaded fastener such as a bolt or nut to tighten or loosen it, when the pawls, disengaged from their respectively engaged ratchet teeth on angular movement of the handle relative to the inertia member, engage their respective successive ratchet teeth and release thereto as impact energy the energy stored in the spring and conveyed to the pawls by the inertia member, to result in a magnitude of torque delivered to the output shaft, and through it to the engaged threaded fastener, substantially greater than that of the torque applied to the handle by the operator.
Although the said co-pending patent application provides important improvements over the constructions of the impact tools shown in the said patents, this application provides improvements directly related to those of the said co-pending application, as well as additional improvements not so related.